Electronic calculators have become a common tool for teaching students mathematics. In particular, the advantages of graphing calculators are being utilized in the classroom. Graphing calculators are characterized by a larger screen, which permits the entry of mathematical objects in a logical format. They also permit graph displays and table displays. They have sophisticated programming capability. They often permit data transmission to other computing devices, directly or via a data storage medium, as well as data collection via various interface protocols. Particular calculator models are often designed for particular educational levels. For example, a calculator for middle school students might have less advanced features than one designed for older students. However, regardless of the level for which a calculator is designed, a continual goal in designing them is to provide a logical and easy to use interface.
Some prior graphing calculators would allow the user to view a history screen, which is a scrolling display of previous display outputs. However, the user interface for these functions in the prior art was not able to select and incorporate mathematical objects from the history screen.